There's great news for builders, drivers, and racers of 426-style Hemi engines. Stage V Engineering has just introduced the Rat Buster single-plane aluminum intake manifold. Unlike many of the latest aftermarket offerings for the 426-style elephant, the Rat Buster is a dual four-barrel design. We don't know about you, but single four-barrel carburetor manifolds, even those boasting a big Holley Dominator, look lost between the broad-shouldered Hemi's rocker covers, not so with the Rat Buster.
But the classic dual-quad look of the Street Hemi is only part of the Rat Buster story. Because its designers added 2 inches to the distance between the carburetors, the Rat Buster finally allows Hemi owners to explore and enjoy the performance of Holley carburetors without resorting to a cross-ram or tunnel-ram configuration. That's right, you can finally put Holleys on your Hemi, and it all fits underhood.
<strong>Street Hemi Versus Rat Buster Manifold</strong><br>From below, the dual-plane architecture of the vintage Street Hemi intake (left) contrasts sharply with the Rat Buster's single-plane configuration. The rectangular section spanning the two x-forms contains a passage to equalize manifold vacuum between the separate plenums beneath each carburetor.
Best of all, with prices of original '66-'71 Chrysler Street Hemi intake manifolds approaching the stratosphere, the Rat Buster sells for $495. Pretty low bucks, considering it's a modern street/strip design, and it opens a whole new world of carburetion possibilities, while maintaining the classic dual-quad vibe we've come to associate with the mighty 426 and its even larger, stroker-equipped offspring.
To see what the new Rat Buster has to offer, we stuck one on a 520ci Stage V Hemi conversion motor, added a set of short-bowl-equipped Holley 750 vacuum secondary carburetors, and picked up 22 hp over a Vanke-modified '67 Street Hemi intake manifold and dual 750 AFB-style carburetors on the chassis dyno. Comparison testing on an eighth-mile dragstrip of the same motor in a 3,400 pound Dart saw the Rat Buster and Holleys increase trap speed by better than 4 mph and reduce the e.t. by nearly two-tenths of a second. Remember, that's on an eighth-mile track. On a full quarter, these improvements would nearly double. All the while, the Dart's docile street manners and 11-mpg fuel economy remained on par with the Street Hemi/AFB baseline induction combo. These are good times for Hemi fanatics, and the new Stage V Rat Buster makes them even better.
Art Carr Saves The Day
We must extend a hearty thanks to drag racing Torqueflite pioneer Art Carr's California Performance Transmission for reviving the Dart's ailing 727. Midway through testing of the Street Hemi induction, it developed slippage on the 2-3 upshift that threatened to invalidate further data. Art's crew installed new bands and clutches so we could continue.
Street Hemi Versus Rat Buster Manifold